The Kinetic and Molecular Basis for the Interaction of LexA and Activated RecA Revealed by a Fluorescent Amino Acid Probe.

ABSTRACT: The bacterial DNA damage response (the SOS response) is a key pathway involved in antibiotic evasion and a promising target for combating acquired antibiotic resistance. Activation of the SOS response is controlled by two proteins: the repressor LexA and the DNA damage sensor RecA. Following DNA damage, direct interaction between RecA and LexA leads to derepression of the SOS response. However, the exact molecular details of this interaction remain unknown. Here, we employ the fluorescent unnatural amino acid acridonylalanine (Acd) as a minimally perturbing probe of the E. coli RecA:LexA complex. Using LexA labeled with Acd, we report the first kinetic model for the reversible binding of LexA to activated RecA. We also characterize the effects that specific amino acid truncations or

SUBMITTER: Hostetler ZM 

PROVIDER: S-EPMC7230020 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature